| 词条 | 809 Lundia |
| 释义 |
| minorplanet=yes | background=#D6D6D6 | name=809 Lundia | image = 809Lun-LB1-mag17.jpg | image_size = 245 | caption=Asteroid 809 Lundia (apparent magnitude 16.6) near a mag 15.6 star | discoverer=Max Wolf | discovered=11 August 1915 | mpc_name=(809) Lundia | alt_names=1915 XP; 1936 VC | named_after=Lund Observatory | mp_category=Main belt | epoch=31 July 2016 (JD 2457600.5) | semimajor={{Convert|2.28254|AU|Gm|abbr=on}} | perihelion={{Convert|1.84193|AU|Gm|abbr=on}} | aphelion={{Convert|2.72316|AU|Gm|abbr=on|lk=on}} | eccentricity=0.19304 | period=3.45 yr (1259.6 d) | inclination=7.14911° | asc_node=154.580° | arg_peri=196.162° | mean_anomaly=76.7867° | dimensions=10.26 ± 0.07 km[1] | mass={{nowrap|(9.27 ± 3.09) × 1014 kg[1]}} | density=1.64 ± 0.10 g/cm3[1] | rotation={{Convert|15.4142|h|d|abbr=on|lk=on}} | spectral_type=V | abs_magnitude=12.2 | albedo= | mean_motion={{Deg2DMS|0.285809|sup=ms}} / day | orbit_ref= | observation_arc=100.48 yr (36700 d) | uncertainty=0 }} 809 Lundia is a small, binary, V-type asteroid[1] orbiting within the Flora family in the main belt. It is named after Lund Observatory, Sweden. CharacteristicsLundia orbits within the Flora family. However, its V-type spectrum indicates that it is not genetically related to the Flora family, but rather is probably a fragment (two fragments, if its moon is included) ejected from the surface of 4 Vesta by a large impact in the past. Its orbit lies too far from Vesta for it to actually be a member of the Vesta family. It is not clear how it arrived at an orbit so far from Vesta, but other examples of V-type asteroids orbiting fairly far from their parent body are known. A mechanism of interplay between the Yarkovsky effect and nonlinear secular resonances (primarily involving Jupiter and Saturn) has been proposed.[2] Binary systemLightcurve observations in 2005 revealed that Lundia is a binary system of two similarly sized objects orbiting their common centre of gravity. "Lundia" now refers to one of the objects, the other being provisionally designated S/2005 (809) 1. The similarity of size between the two components is suspected because during mutual occultations the brightness drops by a similar amount independently of which component is hidden.[3] Due to the similar size of the primary and secondary the Minor Planet Center lists this as a binary companion.[4]Assuming an albedo similar to 4 Vesta (around 0.4) suggests that the components are about 7 km across. They orbit each other in a period of 15.4 hours,[3] which roughly indicates that the separation between them is very close: to the order of 10–20 km if typical asteroid albedo and density values are assumed. References1. ^{{cite journal | author= M. Florczak | author2= D. Lazarro | author3= R. Duffard | last-author-amp= yes| title= Discovering New V-Type Asteroids in the Vicinity of 4 Vesta| journal= Icarus| date= 2002| volume= 159| pages= 178–182| doi= 10.1006/icar.2002.6913| bibcode=2002Icar..159..178F}} [5]2. ^{{cite journal | author= V. Carruba| title= On the V-type asteroids outside the Vesta family| journal= Astronomy & Astrophysics| date= 2005| volume= 441| pages= 819–829| doi= 10.1051/0004-6361:20053355| bibcode=2005A&A...441..819C | name-list-format=vanc | display-authors= 1 | last2= Michtchenko | first2= T. A. | last3= Roig | first3= F. | last4= Ferraz-Mello | first4= S. | last5= Nesvorný | first5= D. | issue= 2|arxiv = astro-ph/0506656 }} 3. ^1 Poznań observatory {{cite web |url=http://www.astro.amu.edu.pl/Science/Asteroids/ |title=Archived copy |accessdate=2001-07-02 |deadurl=yes |archiveurl=https://web.archive.org/web/20010702144940/http://www.astro.amu.edu.pl/Science/Asteroids/ |archivedate=2001-07-02 |df= }} (Lightcurve showing signature of the binary) 4. ^{{cite web |title=Satellites and Companions of Minor Planets |publisher=IAU / Central Bureau for Astronomical Telegrams |url=http://www.cbat.eps.harvard.edu/minorsats.html |accessdate=2011-07-03 |deadurl=yes |archiveurl=https://web.archive.org/web/20110121153650/http://www.cbat.eps.harvard.edu/minorsats.html |archivedate=2011-01-21 |df= }} 5. ^1 2 3 {{Citation | first1 = B. | last1 = Carry | title = Density of asteroids | work = Planetary and Space Science | volume = 73 | pages = 98–118 |date=December 2012 | doi = 10.1016/j.pss.2012.03.009 | bibcode = 2012P&SS...73...98C | postscript= .|arxiv = 1203.4336 }} See Table 1. }} External links
7 : Flora asteroids|Discoveries by Max Wolf|Minor planets named for places|Named minor planets|Binary asteroids|V-type asteroids|Astronomical objects discovered in 1915 |
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